Apparatus for gas calorimetry



Oct. 24, 1939. J. G; STEWART APPARATUS FOR GAS CALORIMETRY v 2 Sheets-Sheet l Filed Feb; 8, 1938 au 2 2.a as

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APPARATUS FOR GAS CALORIMETRY Filed Feb. 8. 1938 2 Sheets-Sheet 2 IHVENTOR. f

JAMES GIBB STEWART sa# M c)p A'ITORHEYS UNITED STATES PATENT APPARATUS FOR GAS CALORIMETRY James Gibb Stewart, Letchworth, England; An-

nabella Mitchell Stewart, Hugh McCracken, Jack and Mary Widgery, all executors of said Stewart, deceased Application February 8, 1938, Serial No. 189,416 In Great Britain February l2, 1937 9 Claims. (Cl. 221-96) LThis invention relates to apparatus for congas calorimeter has a first piston pump for sup- 'tinuous recording :gas calorimetry and is more plying the gas to be tested at a particular rate particularly concerned with that portion of the and a second piston pump for supplying the apparatus responsible for the supply of the gas liquid employed in the test at a rate which nors and the liquid medium usually employed in gas mally bears a iixed relation to said particular calorimetry for kdetermining temperature rise. rate of gas supply, and there is means acting in In gas calorimeters of the kind to which the inassociation with one of the pumps for controlling vention relates, it is the aim to supply lthe gas the rate of output according to the local baro- Iundergoing test to the calorimeter at a particumetio pressure and temperature conditions.

10 'lar rate, at standard temperature and pressure, Other aspects of the invention will become ap- 1'0 to supply the liquid medium at a known rate, parent from the claims which follow. t will `whose relation to "the rate of gas supply is conbe understood that the liquid medium employed stant, `and by measurement of the temperature in the testing will normally be water, but that difference in the liquid medium before and after other liquids, such as oil, might advantageously itsentry into rthe lcalorimeter heat interchanger, be used. For the purposes of specific descrip- "15 to obtain a Vcontinuous determination of the tion of apparatus, it will be assumed that water caloric value of the gas. is the liquid in question, but this is not to be For the successful working of a gas calorimeter taken as a limitative statement. vthe rate of flow of the gas and the liquid medium In order that the said invention may be clearmust, of course, be so adjusted as to take into ly understood and readily carried into effect the Q20 account thevariations in volume of the gas with same will now be more fully described with refchanges in temperature and pressure. To comerence to the accompanying drawings, in which: pensate for changes in local barcmetric pres- Figure 1 shows partly in section a diagramsure and temperature there may be used the matic side view of a gas calorimeter according method of diminishing the liquid flow or nto the invention and Figures 2 and 3 are sec- /25 creasingfthe actual volumetric ow of gas as the tional plan views of pumps employed in the temperature vrises or the barometer falls, and apparatus 0f Figure 1- viceversa, f In Figure 1 of the drawings that portion of In gas ealorimeters of the type with which the calorimeter apparatus which actually inthe invention is concerned, it hasbeen the praccludes the calorimeter and the recording mech- IBO tice to dole out the liquid medium by weighing, anism, is shown to a reduced scale, as compared .or volumetrically by ladling, or by liquid dis- `with the remaining part of the apparatus con- Aplacement methods. In the weighing mood, surcerned with the supplying of the gas and water 'face tension can prevent uniform emptying of to the calorimeter, the supply apparatus being 'the weighing vessel, and 'in the ladling method that with which the invention is essentially con- `35 surfacetensicn can make 'the'level of the surface cerned.

of the water Ain the ladle indenite. It is kone The supply apparatus is driven from an elec- "aim of this invention to overcome such errors tric motor I having a driving pulley 2 connected inwater measurement. by means of a belt 3 with a driven `pulley 4.

40 In the past 'the measurement of the gas has The latter is carried upon a shaft 5 whichalso 40 been eiected by externally driving a liquid sealed carries a gear-wheel 6. The latter meshes with drum meter V.as a pump, or by limiting the rate a further gear-wheel 'I secured upon the drivof the same type of gas meter operated by gas ing shaft of a multiple piston rotary pump 8. Ypressure by use of a clock escapement; or by sub- This driving shaft is indicated at 8A in Figure 2 stituting for the driven drum meter a driven which is a sectional plan of the pump 8. The 45 set of liquid sealed bells which riseand fall relapump 8 is of the type having a rotating block 9 tively to theliquid seal and which are arranged formed with cylinders Ill for the reception of to vpump gas at "the required rate. Liquid dispistons I I. Each piston II is mechanically con- 'placement methods have also been employed. nected with the one that is diametrically oppo- \A11these methods require liquid seals and it is site to it so as to aiord two pairs of vcoupled 50 yonefeature of the invention that such liquid pistons, the couplings being shown at IIA. The

:seals are dispensed with, and errors ldue to varibody I2 of the pump casing has an inlet chamation in the level of the sealing liquid are eliznber I3 and an outlet chamber I4. In the pump nated. there is arranged a crank-pin I5 carried ecl545 Following the principles Vof the invention, a centrically upon a boss ISA that lits in an aper- 55 ture formed in a part of the pump body casing I2, and which has a plate I5B secured to it. The plate I5B may be turned by hand to any desired angular setting, so as to adjust the crank-pin I5 in regard to its eccentricity, to afford a variation in the stroke of the pistons of the pump 8. The crank-pin I5 has secured rotatably on it a block I6 engaging between the pistons of each piston pair.

A pump I1, of the same nature as the pump 8, has a driving pinion I8 meshing with a pinion I9 which in turn engages with the pinion 1 so that the pump I1 is indirectly driven from the motor I.

The pump 8 is intended for the supply of water to the calorimeter apparatus proper, and has an inlet pipe 20 and an outlet pipe 2I. The outlet pipe 2I includes a thermometer pocket 22 housing a thermometer 23, and extends flnally to a vessel 24. There is an outlet pipe 25 connected from the bottom of the vessel 24 to the lower end of a heat interchanger unit 26, wherein the gas whose caloric value is to be continuously determined, is burnt to yield up heat to the water introduced into the unit by the pipe 25, all in known manner. There is an outlet pipe 21 from the unit 26 such pipe 21 communieating with the upper end of a second vessel 28 of the same character as the vessel 24. The bottom of the vessel 28 has an outlet pipe 29 communicating with it and extending to a reservoir 30 from whence there is a connecting pipe 3| to a radiator 32. A fan 33 is arranged to cool the radiator 32, and the water which has passed through the radiator emerges through a pipe 34 leading to a vessel 35 in which the body of the pump I1 is immersed. A pipe 36 communicates also with the vessel 35 and with the inlet 20 to the pump 8.

For the purpose of carrying out the continuous recording, the Vessel 24 has arranged within .it a bi-metallic member 40 which is pivoted at 4I.

There is a mechanical connecting member 42 extending between one strip of the bi-metallic member 40 and a strip of a second bi-metallic member 43 disposed in the vessel 28. The bimetallic member 43 is anchored adjustably to a fixed block 44 associated with the vessel 26. The bi-metallic member 40 is connected also by a mechanical transmission element 45 withv one end of a recording pen-holder 46 of a mechanical recorder of known construction. Only the recording surface 41 is indicated, but it will be understood that any known form of mechanical recording mechanism is here applicable.

The pump I1 has an inlet and an outlet pipe, 48 and 49 respectively, the pipe 49 communicating with the gas inlet connection 5I) of the unit 26. The inlet pipe 48 is connected with an external gas supply conduit (not shown).

The pump I1, as already indicated above, is

constructed in the same manner as the pump 8.

The pump I1 is shown in sectional plan in Figure 3 and it will be unnecessary to describe all the working parts thereof since they are mainly the same as those described above with refervence `to Figure 2. The pump I1 has, however,

vwhich extends to a point outside the casing of the pump I1 and which has secured to it one vend of an arm 54. The pivot 53 is carried in a sleeve 53A which is provided with a gland 53B secured removably in the pump body casing. The end of the arm 54 that is more distant from the pin 53 is connected to a rod 55, which is in turn connected to the end 56 of a centrally fulcrumed lever 51, the latter being pivoted between the cheeks of a xed yoke 58, at 59. At the end of the lever 51 that is remote from its pivotal connection 56, there is a further pivotal connection 69 to the upper end of a cylindrical bell 6I. The upper end of the latter is closed but at itsA lower end it is left open and enters a vessel 62 containing mercury, as at 63. The vessel 62 has an upstanding cylindrical portion 64 to the interior of which no mercury is admitted. 'Ihe mercury therefore rises between the interior'cylindrical wall of the bell 6I and the external cylindrical wall of the member 64. Just above its pivot point 59, the lever 51 carries a weight 65.

When the apparatus is in operation the motor I is supplied with electric current from any convenient current source and drives the pinion 6 through the intermediary of the pulleys 2 and 4 and the belt 3. The pinion 6 rotates the meshing pinion 1 which in turn actuates the pinion I9 meshing with the pinion I8. In thisy waythe pumps 8' and I'Ir are both driven from a common source of power, their relative speeds of actuation depending upon the gear ratio of the intermediate transmission. The stroke of the kpistons II of the pump 8 relative to their respective cylinders I0 will be determined by the eccentric offset of the crank-pin I5. In adjusting the apparatus therefore the crank-pin I5 is brought to a definite position depending upon the desir-ed rate of output from the pump. By the relative motion of the pistons and cylinders, water is drawn into the intake pipe 29 and pumped out through the outlet pipe 2| whence it enters the vessel 24. Prior to entry into such vessel the temperature of the water may be observed from the thermometer 23. The temperature of the water within the vessel 24 will be measured by the deformation produced on the bi-metallic member 40. The water leaves the vessel 24 and enters the heat interchanger unit 26 where the gas undergoing test is being burnt. The temperature of the water'is raised during passage through the interchanger unit and the wateremerges into the vessel 28, the temperature of the water again being indicated by the deformation of the second bimetallic member 43. The connection of the bimetallic members 49 and 43 results in that their joint indication, as expressed by movement of of the crank-pin 5I and in this case such ecf centricity is determined by the atmospheric conditions prevailing in the region of the apparatus. As will be understood the air within thebell 6I and the member 64 will change in volume and density depending upon the local barometric pressure and the local temperature. When the bell 6I rises the equivalent crank radius of the pump I1 will increase by a directly proportionate amount, and similarly when th-e bell 6I. sinks the crank radius-of the pump I1 willjdiminish proportionately. The weight 65 introduced in r themechanical system will have the effect of assisting in-any adjusting movement of the vbell 61|, and may be so adjusted as to produce conditions of equilibrium of the bell 6l where the pressure of the air in the latter is substantially the same as the local atmospheric pressure.

As will be understood, the mechanical differential' recording system described above vmay be replaced by other known recording systems. 'There is,ffor example, the known electrical recording system. f l

The pressure of the gas supply to the pump I1 is kept low, for example in the region'of about 5/3 inch water gauge, and 'the alterations .in the stroke of the pump as produced by the actuation of the lever 54 are made just sufficient to counteract the effects of local changes of temperature and barometric pressure upon the readings recordedupon the continuous recording apparatus. The vessel 35 through which the return water is passed, serves to keep the pump I1 at substantially the local atmospheric temperature, whereby the effects of any frictional heat produced by the pump on the gas will be minimized.

What I claim and desire to secure by Letters Patent of the United States is:

1. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the caloric value, comprising a rst piston pump for producing a particular rate of supply of said liquid medium, a second piston pump for producing a rate of supplyof the gas, which rate normally bears a iixed relation to the said rate of liquid medium supply,l and means effective upon one of said pumps for varying the output'flow therefrom to compensate for local changes in atmospheric temperature and pressure.

2. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and th-e liquid medium employed for determining the calorific value comprising a first piston pump for producing a particular rate of supply of said liquid medium, a second piston pump for normally producing a rate of supply of the gas which rate normally bears a fixed relation to the said rate of liquid medium supply, and means effective upon said second piston pump for varying the output ow therefrom to compensate for local changes in atmospheric temperature and pressure.

3. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the caloric value, comprising a first piston pump for producing a particular rate of supply of said liquid medium, a second pump formed as a rotary multiple piston pump, Vthe stroke of whose pistons may be varied, and `means for adjusting such stroke in accordance with the local atmospheric pressure and temperature.

4. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the caloric value, comprising a iirst piston pump for producing a particular rate of supply of said liquid medium, a second piston pump for normally producing a rate of supply of the gas, which rate normally bears a xed relation to the said rate of liquid medium supply, a movable bell member containing gas and sealed at its open end by a body of liquid which is otherwise open to the atmosphere, a control element upon said second pump, said control element by its movement adjusting the rate of output of said second pump, connecting means arranged between said bell member and control element to produce movement of the control element according to the movements experienced by the bell member as a result of volume changes, brought about by local atmospheric conditions, in the gas within said bell member.

5. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employedy for determining the caloriflc value, comprising a rst piston pump for producing a particular rate of supply of said liquid medium, asecond pump for producing a rate of supply of the gas, which rate normally bears a fixed relation to the said rate of liquid medium supply, a bell member suspended with its mouth sealed by a body of liquid which is otherwise exposed to the atmosphere, means for counterbalancing the bell member to assure that the gas contained therein is substantially at the local barometric pressure, a control element upon said second pump for varying the rate of output therefrom and a mechanical connection between said control member and said bell member to allow the control member to be moved according to the movement of the bell member.

6. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the caloric value, comprising a first piston pump for producing a particular rate of supply of said liquid medium, a second pump which is formed as a rotary multiple piston pump and which produces a rate of supply of gas bearing a normally fixed relation to the rate of liquid supply, a crank member whose eccentricity with respect to the pump may be varied to produce a greater or lesser stroke of said pump, a control element for displacing the crank member, a bell whose open end is allowed to depend into a body of liquid which is otherwise open to the atmosphere, and a mechanical connection between the bell and said control elements to influence the position of the control elements according to the position assumed by the bell due to the gas which is contained therein and which changes in volume according to the local temperature and pressure.

'7. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the calorific value, comprising a rst rotary multiple piston pump having an adjustable crank member to determine the throw of the pistons, a source of motive power for driving said rst pump, mechanical transmission between said first pump and a second pump also formed as a multiple piston rotary pump, a secondicrank member associated with said second pump, said second crank member being adjustable to vary the throw of the pistons thereof, a control element arranged to displace said second crank member upon movement of the control element, a vertically movable bell arranged to depend with its open end over a body of liquid which is otherwise open to the atmosphere, a counterbalance system for supporting said bell to assure that gas trapped therein shall be at substantially atmospheric pressure, a mechanical connection between the bell and the control element, so that the position of the latter is determined by the position of the bell.

8. In apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the calorific value, comprising a first piston pump for producingv a particular rate of supply of said liquid medium, a second pump for producing a rate of supply of the gas, which rate normally bears a xed relation to the said rate of liquid medium supply, means eiTectiVe upon said second pump for Varying the output flow therefrom to compensate for local changes in atmospheric temperature and pressure, and a container for enclosing said second pump and for the reception of liquid which is at substantially the local atmospheric temiperature and which is drawn through said container to the inlet of said rst pump. y

9..In'apparatus for gas calorimetry, means for supplying to the calorimeter apparatus the gas that is to be tested and the liquid medium employed for determining the caloric value, comprising a rst piston pump for the liquid medium supply, a second piston pump for the gas supply, a source of power for driving the pumps, mechanical transmission from said power source to both said pumps, so that the latter are driven in a fixed ratio as regards speed, and means effective upon one of said pumps for Vary` ing the output flow therefrom to compensate for local. changes inatmospheric; temperature and 1-5` pressure.

JAMES GIBB STEWART. 

